"Very, very seldom do you have a reaction like he did," Whisenhunt said. "So there is really nothing wrong with his knee. It's just about getting the swelling out."

On Thursday, Wells said his knee felt better and that he was hopeful of practicing Friday and playing Sunday against the Vikings.

"We were just going to try something new and it backfired," Wells said.

Wells started his first NFL game last Sunday and was expected to start against the Vikings. But he experienced swelling in the knee after an injection Monday and was listed as "limited" after the past two practices.

Wells said he is confident he could practice today and then "fully execute the game plan," he said. "You want to go out there and play full speed, not swelling up to where I can't bend my knee."

Whisenhunt said Wells needs to practice "a little more tomorrow (Friday) in order to make us feel more comfortable about him playing."

Outside linebacker Clark Haggans (groin) did not practice Thursday and likely will miss a second consecutive game. For the Vikings, quarterback Brett Favre (foot/ankle/chin) was limited on Thursday and receiver Percy Harvin (ankle) did not practice.

A family affair

Safety Hamza Abdullah will have a family reunion of sorts Sunday at Mall of America Field. Abdullah's younger brother, Husain, is the starting strong safety for the Vikings.

"We're going to have quite a big family there," Hamza Abdullah said. "It's our first time facing each other in the NFL, so it's a big matchup."

Hamza Abdullah has been inactive in five games this season, but said he wouldn't lobby coaches to play him against the Vikings.

The brothers don't have anything wagered on the game. "But I'm sure in the off-season it's going to come up a few times," Hamza Abdullah said.

His next life

Cardinals outside linebacker Joey Porter isn't complaining about his career. He's in his 12th season and is still playing at age 33.

But if he had to switch places with anyone, it would be Favre.

"He has the best situation: when they don't let you retire and they give you more money each year for you to play," Porter said. "He's got the best of both worlds. He don't do training camp and he comes back and says it's not about the money, but gets more than he's originally supposed to get. You can't be mad at a guy for beating the system."